Elon Musk has laid out the first detailed design of SpaceX's AI1 satellite in a 30-minute video posted to the company's X account, the opening generation of an orbital craft SpaceX wants to build by the million to run AI workloads off Earth's power grid. Carrying a 150 kW peak compute payload across a 70-meter deployed wingspan, the spacecraft uses an interchangeable hardware design that lets different chipmakers supply the processors. The timing of this announcement is no accident, coming just three days before SpaceX’s IPO, which is set to price on June 11th and trade on June 12th at a target valuation near $1.75 trillion.

In his announcement, Musk pegged the satellite’s compute payload at roughly the draw of a single Nvidia GB300 rack, which pulls around 140 kW on the ground. One AI1, in those terms, is about one rack in orbit. In terms of its overall specs, SpaceX disclosed an average compute payload of 120 kW, a peak of 150 kW, and a density of 70 kW per ton, with the craft operating at roughly 600 km.

A satellite with these specs comes with some serious space requirements, and its 70-meter deployed wingspan edges past the 68.4-meter span of a Boeing 747-8. As for the interchangeable compute, that leaves the platform open to whichever vendor ships the most competitive AI silicon, rather than locking it to a single supplier.

This interchangeability is no doubt important to Musk, not least because SpaceX can’t yet guarantee its own supply of chips. The company is currently building Terafab, a chip fab that’s running as a joint venture with Tesla, while its S-1 IPO filing warns it can’t currently secure enough chips.

That aside, the elephant in the room is cooling: a rack on Earth sheds heat into moving air and circulating water, neither of which exists in a vacuum, where the only viable route is radiating it away as infrared. AI1 features up to 110 m² of deployable liquid radiators, as well as redundant pumping loops and integrated micrometeroid shielding. By comparison, the International Space Station’s ETACS rejects roughly 70 kW of heat — around half of what’s needed to cool a 140 kW GB300 rack — across 422 m² of radiator at a cost of up to $500 million, according to SemiAnalysis.

Musk has previously waved off potential thermal critiques, telling SpaceNews back in March that it's "safe to say SpaceX knows how to do heat rejection in space" and pointing to the company's fleet of more than 10,000 Starlink satellites.

SpaceX filed with the FCC in January to launch up to a million orbital data center satellites and has already signed compute deals, including a $920 million-per-month agreement with Google. The model has prominent skeptics: OpenAI's Sam Altman called orbital data centers "ridiculous" earlier this year.

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Luke James is a freelance writer and journalist.  Although his background is in legal, he has a personal interest in all things tech, especially hardware and microelectronics, and anything regulatory.